An image forming apparatus such as a copying apparatus, a printer, a facsimile apparatus, an MFP (Multi-Function Peripheral), or the like, often employs a system in which a part for accommodating a toner that is an example of image forming powder is provided in a form of a unit that can be attached (or loaded) and detached (or unloaded) with respect to a base unit or the like of the image forming apparatus.
According to this system, when the unit accommodating the toner is attached to the other unit, openings provided in the two units are connected so that the toner can be exchanged through the two openings. On the other hand, in a state in which the two units are detached from each other, the connection of the openings of the two units is released, and it is desirable to prevent the toner from leaking from the openings. For this reason, in general, a shutter is provided to close each of the openings, as proposed in PTL 1 (Japanese Laid-Open Patent Publication No. 9-274352), for example.